| 摘要 |
<P>PROBLEM TO BE SOLVED: To easily enlarge the normally functioning range of an autofocus operation. <P>SOLUTION: A focus detecting device is equipped with: a means to illuminate an object surface (11) via a first field stop 16; first imaging means (19, 20, 41) which form the intermediate image of the first field stop on the basis of light L2 exiting from the object surface onto a plane where a second field stop 41 is placed, make the intermediate image pass through without interception by the second field stop when the object surface is placed within a predetermined range including a focal plane, and intercept part of the intermediate image by the second field stop and make the rest of the image pass through when the object surface is placed out of the predetermined range; second imaging means (42 to 46) which halve the final image of the first field stop in two on the basis of light L5 from the first imaging means; and generating means (47, 48) which detect the distance between halved final images in two and generate focus signals according to the positional relation of the object surface with respect to the focal plane. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
